<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>map&&reduce</title>
    <script>
        let arr = ['1','20','-5','3'];
        console.log(arr);

        arr = arr.map(s => parseInt(s));

        console.log(arr)
        const arr1 = [1,20,-5,3];
        let result = arr1.reduce((a,b)=>a/b);
        console.log(result)
    </script>
</head>
<body>

</body>
</html>